Individuals can sometimes sustain an injury to tissue, such as cartilage, muscle, bone, and sinew that requires repair by surgical intervention. Such repairs can be effected by suturing or otherwise repairing the damaged tissue, and/or by augmenting the damaged tissue with other tissue or with a tissue implant. The implant can provide structural support to the damaged tissue.
One example of a common tissue injury concerns damage to cartilage, for example, the menisci of a knee joint. There are two menisci of the knee joint, a medial and a lateral meniscus. The meniscus is a biconcave, fibrocartilage tissue that is interposed between the femur and tibia of the leg. The primary functions of the meniscus are to bear loads, absorb shock, stabilize, and lubricate the joint. If not treated properly, an injury to the meniscus, such as a “bucket-handle tear,” can lead to the development of osteoarthritis. Currently, treatment modalities for a damaged meniscus include removal of the meniscus and surgical repair of the damaged meniscus.
Another common tissue injury is a damaged or torn rotator cuff, which facilitates circular motion of the humerus bone relative to the scapula. The most common injury associated with the rotator cuff is a strain or tear to the supraspinatus tendon. This tear can be at the insertion site of the tendon with the humerus, thereby releasing the tendon partially, or fully (depending upon the severity of the injury), from the bone. Additionally, the strain or tear can occur within the tendon itself. Treatment for a strained tendon usually involves physical cessation from use of the tendon. However, depending upon the severity of the injury, a torn tendon might require surgical intervention as in the case of a full tear of the supraspinatus tendon from the humerus. Surgical intervention can involve the repair and/or reattachment of torn tissue. A prolonged recovery period often follows repair of a rotator cuff injury.
Surgical treatment of damaged tissue (e.g., the menisci, ligaments, and tendons) would benefit from techniques that effect a more reliable repair of tissue, and which facilitate more rapid healing. Thus, various implants have been used in surgical procedures to help achieve these benefits. Examples of such implants include those that are made from biologically derived tissue (e.g., allografts and autografts), and those that are synthetic. Biologically derived materials can have disadvantages in that they can contribute to disease transmission, while synthetic materials are difficult to manufacture in such a way that their properties are reproducible from batch to batch.
Various known devices and techniques for treating such conditions have been described in the prior art. For example, Naughton et al. (U.S. Pat. No. 5,842,477) describe an in vivo method of making and/or repairing cartilage by implanting a biocompatible structure in combination with periosteal/perichondrial tissue which facilitates the securing of the implant.
Various tissue reinforcing materials are disclosed in U.S. Pat. No. 5,891,558 (Bell et al.) and European Patent Application No. 0 274 898 A2 (Hinsch). Bell et al. describe biopolymer foams and foam constructs that can be used in tissue repair and reconstruction. Hinsch describes an open cell, foam-like implant made from resorbable materials, which has one or more textile reinforcing elements embedded therein. Although potentially useful, the implant material is believed to lack sufficient strength and structural integrity to be effectively used as a tissue repair implant.
Despite existing technology, there continues to be a need for devices and methods for securing damaged tissue and facilitating rapid healing of the damaged tissue.